Profiled Blade, Fan Wheel and Method for Producing a Profiled Blade

ABSTRACT

Profiled blade for a fan wheel, with a profile body produced from at least one curved metal strip, whereby adjacent end zones of the at least one metal strip are connected to each other in an adhesively bonded and/or form-fit manner wherein a second end zone at a distance from a second end zone edge is equipped with at least one embossed area for forming a contact surface enabling a first end zone to, at least in sections, be brought into contact with it.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims foreign priority under 35 U.S.C. §119(a)-(d) to Application No. DE 102016202894.4 filed on Feb. 24, 2016, and also claims priority to Application No. EP 16161650.3 filed on Mar. 22, 2016, the entire contents of which are hereby incorporated by reference.

TECHNICAL FIELD

The description relates to a profiled blade for a fan wheel with a profile body produced from at least one curved metal strip, whereby adjacent end zones of the at least one metal strip are connected to each other in an adhesively bonded and/or form-fit manner. In addition, the description relates to a fan wheel and a method for producing a profiled blade.

BACKGROUND

According to a conventional approach known to the applicant but not laid down in a printed publication, profiled blades for fan wheels are produced in a cost-effective manner by a preferably rectangularly shaped metal strip being bent at least in a bending zone located approximately in the middle of the metal strip, at right angles to a longest edge. In this bending process, opposing first and second end zone edges of the metal strip are brought close to each other. For this bending process it is possible to use for example a bending device with the aid of which a cylinder barrel section-shaped leading edge with an essentially semi-cylindrical cross section is created in the bending zone. In the course of the bending process, a U-shaped profile is temporarily generated which, through the continuation of the bending process, is changed into a drop-shaped profile. This drop-shaped profile constitutes the final state of the bending process. In a subsequent processing step, an adhesively bonded and/or form-fit connection of the adjacent end zone edges of the metal strip can then be provided in order to produce a stable profiled blade. By way of an example, it is provided that the adjacent end zone edges of the metal strip are to be welded and/or glued and/or clinched together.

SUMMARY

An object of the described system involves providing a profiled blade, a fan wheel with such profiled blades and a method for producing a profiled blade with which, while retaining the cost-effective production method, improved rigidity can be achieved for the profiled blades.

This object is achieved for a profiled blade for a fan wheel, with a profile body made from at least one curved metal strip, whereby adjacent end zones of the least one metal strip are connected in an adhesively bonded and/or form-fit manner to each other, wherein a second end zone is equipped with at least one embossed area at a distance from a second end zone edge for the formation of a contact surface to enable an at least partial contact with a first end zone.

The at least one embossed area performs a dual function, since it on the one hand enlarges a contact surface for the first end zone, to be connected in an adhesively bonded manner, with the upper side of the second end zone and since it, on the other hand, leads to a reinforcement of the rigidity of the second end zone, without one having to accept significant aerodynamic disadvantages as a result. Preferably at least one embossed area in one of the end zones is designed such that its contact surface facing the other respective end zone is, at least in sections, aligned parallel to a section of the respective end zone adjacent to the end zone edge or originating from the end zone edge. By way of an example, the embossed area is designed as an arrangement of folds of the respective end zone, preferably each aligned parallel to the end edge and in particular in opposing directions. By way of an example, the at least one embossed area can also contain one or more through-holes through the metal strip, as a result of which for example tongues protruding from the surface of the second end zone are formed with which the first end zone edge can be brought into contact or behind which the first end zone edge can be pushed. By way of an example, embossed areas arranged alternately are provided on both end zones.

Preferably it is provided that a first end zone edge of a first end zone is arranged at a distance from a second end zone edge of a second end zone and that the first end zone edge is fixed on an upper side of the second end zone facing towards the first end zone.

With this measure, the circumstance is achieved of there being a larger connection surface available for the adhesive bonding connection (welding, gluing) of the two end zones than is the case if, as per the prior art, the two end zone edges are placed against one another and connected to each other. In addition, depending on the connection method provided, in particular welding methods or gluing methods, the connection process can be carried out with improved process reliability, since the upper side of the second end zone supports the supply of a filler metal and/or of an adhesive and/or a welding nozzle of a welding device can be placed on the upper side of the second end zone while the welding process is being carried out. In addition, thermal distortion which may occur with an adhesively bonded connection of the end zone edges through welding is reduced through this measure. The distance from the first end zone edge to the second end zone edge can be chosen to be constant across the entire edge length or vary; this is particularly dependent on the profile geometry of the profiled blade. With a basic form of the profiled blade, a constant profile of the profile body along a profile axis is provided; the profile body has, in cross-sectional planes parallel to each other which are each aligned perpendicular to the profile axis, a constant cross section. With a variation of this basic form it can be provided that the profile body has, in cross-sectional planes parallel to each other which are each aligned perpendicular to the profile axis, variable cross sections. Such a profile blade may for example have surfaces with multi-dimensional curvatures, as are used for example for high-performance fan wheels. Preferably it is provided that the first end zone edge is arranged in the immediate vicinity of a bending edge of the embossed area incorporated in the second end zone.

It is useful if the profile body has a first, in particular plate-shaped profiled part enclosing the first end zone, which (part) is connected to a sleeve-shaped, highly curved leading edge which is connected to a second, in particular plate-shaped profiled part which ends at the second end zone. Here the two profiled parts and the leading edge are preferably designed as one piece and simply constitute differently curved zones of the at least one shaped metal strip. By way of an example, the leading edge may be shaped in the manner of a section of a cylinder barrel and has, relative to a profile axis, a curvature radius that is at least essentially constant. Other profiles of the leading edge which for example correspond to a wing leading edge of an airfoil for an airplane wing, may also be provided.

In a further development of the described system, it is provided that the leading edge has an outer surface with a convex curvature and/or that the first profiled part has an outer surface with a convex curvature and/or that the second profiled part has an outer surface with a concave curvature.

It is advantageous if the embossed area is designed as corrugation and/or is located at a distance from, in particular in parallel to, the second end zone edge. A corrugation should be understood to mean a closed embossed area which has, along a profile axis in parallel cross-sectional planes aligned perpendicular to the profile axis, a constant cross section and in which no through-holes are provided in the metal strip. Variants for a corrugation may provide that the embossed area has a change in cross section along the profile axis, for example that the corrugation, starting from a deep embossed area at one end of the end zone edge completely disappears as it reaches the other end of the end zone edge. Through the design of the embossed area as corrugation an advantageous stabilization of the second end zone can be achieved. In addition, with the use of corrugation as an embossed area in the second end zone, no undesired crossflows occur during use of the profiled blade in a fan wheel which could lead to aerodynamic losses and possibly undesired noises.

With an advantageous development of the described system it is provided that the embossed area protrudes from the upper side of the second end zone, in particular with an L-shaped profile. Preferably it is provided that a longer side of the L-shaped profile faces towards the second end zone edge of the second end zone and forms, with the surface of the second end zone, a sharp angle in an angle range of greater than 0 degrees up to 20 degrees. A shorter side of the L-shaped profile forms, by way of an example, an angle of approx. 90 degrees with respect to the longer side and points in the direction of the leading edge. With such a design of the embossed area, the first end zone lies flat against the, in particular rectangular, upper side of the longer side of the L-shaped profile and thereby enables an advantageous flat and stable connection of the two end zones of the metal strip.

It is useful if the embossed area is recessed in the upper side of the second end zone, in particular with an L-shaped profile. With this version of an embossed area, the shorter side of the L-shaped profile points in the direction of the second end zone edge, whilst the longer side of the L-shaped profile points in the direction of the leading edge. The end zone edge of the first end zone contacts, in this embodiment, with the—in particular rectangular—upper side of the longer side of the L-shaped profile and in this zone is connected in a flat, stable manner to the second end zone.

Preferably it is provided that the profile body is designed open on the front side and/or is formed from precisely one one-piece, bent metal strip. By this mechanism, a cost-effective design of the profiled blade is enabled which in a subsequent processing step is in any case connected to a round plate and a ring of a fan wheel on the front side, by which the front sides of the profile body are at least almost completely sealed. With a one-piece design of the profiled blade from precisely one metal strip, cost-effective manufacture can likewise be guaranteed.

In a further implementation, it is provided that the first end zone edge is welded and/or glued to the upper side of the second end zone facing towards the first end zone.

The object of the described system is achieved for a fan wheel for the transport of a gaseous fluid. Here the fan wheel comprises a disc-shaped round plate which is constructed coaxially to an axis of rotation and which for its part comprises a hub arrangement. Also provided are a ring arranged coaxially to the axis of rotation and at a distance from the metal plate, and several profiled blades according to the system arranged in a pre-settable angular division in a ring-shaped spatial volume around the axis of rotation, fixed with axial, opposing faces on the round plate and on the ring. Such a fan wheel is for example set with its hub arrangement on an electric drive motor and accommodated in a blower case equipped with entry openings and exit openings, in order to be able to generate a fluid flow, in particular an air flow, during rotation around the axis of rotation. Typical applications for such fan wheels are hot-air ovens, steamers, heating burners and air-conditioning units.

With an advantageous development of the fan wheel it is provided that the profiled blades each have a leading edge arranged radially inward in the ring-shaped spatial volume and first end zones and second end zones arranged radially outward in the ring-shaped spatial volume.

A method for the production of a profiled blade comprises the following steps: supplying a metal strip to an embossing device, carrying out an embossing process to emboss an embossed area into a second end zone of the metal strip, in particular at a distance from a second end zone edge, supplying the embossed metal strip to a metal forming device and deforming the metal strip to form a leading edge, a first profiled part and a second profiled part, bringing a first end zone edge of a first end zone into contact with an upper side of the second end zone facing towards the first end zone and connecting, in an adhesively bonded manner, the first end zone edge to the upper side of the second end zone by adhesive bonding.

In one development of the method, it is provided that with the implementation of the embossing process, the deformation of the metal strip and/or a separating process for separating the metal strip from a metal sheet are performed.

In one development of the method, it is provided that the first end zone edge is welded to the upper side of the second end zone and that profiled blades formed as a result are each welded, on the front side, to a disc-shaped round plate and to a ring arranged coaxially to and at a distance from the round plate, in each case along a profile outer side that goes all the way round.

BRIEF DESCRIPTION OF THE DRAWINGS

Advantageous implementations of the described system are shown in the following drawing figures:

FIG. 1 is a perspective view of a conventional profiled blade;

FIG. 2 is a perspective view of a first embodiment of a profiled blade, in which a first end zone edge of a first end zone lies flat against a recessed embossed area in an upper side of a second end zone;

FIG. 3 is a perspective view of a second embodiment of a profiled blade, in which a first end zone edge of a first end zone lies flat against a raised embossed area in an upper side of a second end zone;

FIG. 3a is a perspective detailed view of a version of the second embodiment of a profiled blade shown in FIG. 3, in which the second end zone is shortened compared with the embodiment of FIG. 3, so that the two end zone edges are arranged immediately adjacent to each other;

FIG. 4 is a perspective, partly broken, view of a fourth embodiment of a profiled blade in which a first end zone edge of a first end zone lies flat against a plurality of embossed areas in an upper side of a second end zone;

FIG. 5 is a perspective view of a fan wheel which is equipped with profiled blades according to the embodiment shown in FIG. 2;

FIG. 6 is a perspective, partly broken view of a fifth embodiment of a profiled blade in which a first end zone edge of a first end zone contacts in sections with an embossed area formed in an upper side of a second end zone;

FIG. 7 is a perspective, partly broken view of a sixth embodiment of a profiled blade which is designed as a version of the fifth embodiment of the profiled blade and in which stiffening edge embossing is assigned to the embossed area in the upper side of the second end zone; and

FIG. 8 is a perspective view of a seventh embodiment of a profiled blade which is designed as a version of the sixth embodiment of the profiled blade and in which an embossed area into a lower side of the first end zone is equipped with stiffening edge embossing.

DETAILED DESCRIPTION

With the embodiments of profiled blades 1, 21, 41, 41 a, 61, 101, 121, 141 described in more detail below, the same reference symbols are used for structures with the same function, in each case increased by 20. A description of the respective structures is given only once in each case. Firstly an explanation is given of a profiled blade 1 known from the prior art, with the aid of which the basic components of the profiled blades 21, 41, 41 a, 61, 101, 121, 141 according to the described system and shown in FIGS. 2 to 8 are revealed.

A conventional profiled blade 1 shown in FIG. 1 is, purely by way of an example, produced from a rectangular metal strip 2. The metal strip 2 comprises two longest sides 3, 4 and two end zone edges 5, 6. The longest edges 3, 4 are each aligned at right angles to the end zone edges 5, 6. The metal strip 2 may for example be produced as a section of a strip material (not shown) or as a section from a metal sheet (not shown) and has been bent in a place slightly away from a central point of the two longest edges 3, 4. Through this reshaping process, a profile body 7 has been formed which, purely by way of an example, has a constant profile along a profile axis 8. Through the implementation of the bending process away from the central point of the two longest edges 3, 4, the end zone edge 5 comes to lie at a distance from the end zone edge 6, with the two end zone edges 5, 6 being, purely by way of an example, aligned parallel to one another. As a result of this the upper side 9 of a second end zone 11 originating from the second end zone edge 6 forms a contact surface for the end zone edge 5 of a first end zone 10 originating from this end zone edge 5. By laying the first end zone edge 5 flat on the upper side 9 an adhesively bonded connection between the end zone edge 5 and the upper side 9 is facilitated, regardless of whether an adhesively bonded connection of the end zone edge 5 to the upper side 9 is to be achieved through gluing or welding.

The profile body 7 of the profiled blade 1 shown in FIG. 1 comprises, purely by way of an example, a first profiled part 17 enclosing the first end zone 10 and designed plate-shaped with a convex outer surface, which is connected in one piece with the leading edge 18 that is designed sleeve-shaped and highly curved and which is connected to a second profiled part, designed plate-shaped with a concave outer surface, that ends at the second end zone 11.

With the first embodiment of a profiled blade 21 according to the described system shown in FIG. 2, a first end zone edge 25 of a first end zone 30 is accommodated in an embossed area 32 in an upper side 29 of a second end zone 31. Purely by way of an example, the embossed area 32 is introduced as recesses into the upper side 29 of the second end zone 31, as a result of which it protrudes in a raised manner from the lower side 33 of the second end zone 31. By way of an example, the embossed area 32 has an L-shaped profile along the profile axis 28, with a longer side 34 of the embossed area 32 facing away from the second end zone edge 26, whilst a shorter side 35 of the embossed area 32 faces towards the second end zone edge 26. The first end zone 30 can hence be laid flat on a surface 36 of the embossed area 32, shown hatched in FIG. 1 and purely by way of an example designed as a rectangle, and be connected in an adhesively bonded manner, preferably through gluing or welding, to this surface 36.

With the second embodiment of a profiled blade 41 according to the described system shown in FIG. 3, the embossed area 52 is introduced into the second end zone 51 such that it protrudes in a raised manner from the upper side 49. By way of an example the embossed area 52 has an L-shaped profile along the profile axis 48, with a longer side 54 of the embossed area 52 facing away from the second end zone edge 46, whilst a shorter side 55 of the embossed area 52 faces towards the second end zone edge 46. The first end zone 50 can hence be laid flat on a surface 56 of the embossed area 52, shown hatched in FIG. 2, and purely by way of an example designed as a rectangle, and be connected in an adhesively bonded manner, preferably through gluing or welding, to this surface 56.

The version shown in FIG. 3a of the second embodiment of a profiled blade 41 according to the described system shown in FIG. 3 is a fourth embodiment of a profiled blade 41 a. With the profiled blade 41 a, which otherwise can be designed identically to the profiled blade 41, the embossed area 52 a is—consistent with the profiled blade 41—according to FIG. 3 introduced into the second end zone 51 a in such a way that it protrudes in a raised manner from the upper side 49 a. By way of an example the embossed area 52 a has an L-shaped profile along the profile axis 48 a, with a longer side 54 a of the embossed area 52 a facing away from the second end zone edge 46 a, whilst a shorter edge 55 a of the embossed area 52 a faces towards the second end zone edge 46 a. The first end zone 50 a can hence be laid flat on a surface 56 a of the embossed area 52 a, purely by way of an example designed as a rectangle, and be connected in an adhesively bonded manner, preferably through gluing or welding, to this surface 56 a. At variance with the profiled blade 41 according to FIG. 3, with profiled blade 41 a the second end zone 51 a is designed shortened, so that the two end zone edges 45 a, 46 a are arranged immediately adjacent to one another. Owing to the embossed area 52 a the end zones 50 a, 51 a connected to each other in an adhesively bonded manner have high rigidity; in addition, through the laying-flat of the first end zone 50 a on the surface 56 a of the embossed area 52 a a large strip-shaped connection zone is created which likewise contributes to the stabilisation of the end zones 50 a, 51 a. Here the surface 56 a may optionally be designed flat, as is the case in the depiction of FIG. 3a , or have a bent profile along the profile axis.

In the same manner, the embodiments of profiled blades 22, 62 shown in FIGS. 2 and 4 can be designed with a shortened second end zone, whilst with the embodiments according to FIGS. 6, 7 and 8, such a shortened second end zone is already provided.

With the fourth embodiment of a profiled blade 61 according to the described system shown in FIG. 4, several embossed areas 72 are introduced into the second end zone 71 such that they protrude in a raised manner from the upper side 69. By way of an example, the embossed areas 72 each have an L-shaped profile along the profile axis 68, with a longer side 74 of the embossed areas 72 facing away from the second end zone edge 66, whilst a short side 75 of the embossed areas 72 faces towards the second end zone edge 66. The first end zone 70 can hence be laid flat on surfaces 76 of the embossed areas 72, shown hatched in FIG. 3 and purely by way of an example designed as a rectangle, and connected in an adhesively bonded manner, preferably through gluing or welding, to these surfaces 76. With one version of the profiled blade 61, indicated hatched in FIG. 3, the first end zone 70 is also equipped with embossed areas 78, which are designed for engagement between the embossed areas 72 and, in addition to stabilisation of the first end zone 70, also ensure an enlarged contact surface of the two end zones 70, 71.

With the fifth embodiment of a profiled blade 101 according to the described system shown in FIG. 6, an embossed area 112 is introduced into the second end zone 111 which protrudes in a raised manner in the direction of the first end zone 110. By way of an example, it is provided that the embossed area extends only across part of the edge length of the end zone edge 106 of the second end zone 111, so that the end zone is only slightly bent near the longest edges 103, 104. By way of an example, the embossed area 112 has an L-shaped profile along the profile axis 108, with a longer side 114 of the embossed area 112 facing towards the second end zone edge 106, whilst a shorter side 115 of the embossed area 112 faces away from the second end zone edge 106. The first end zone 110, which on the edge is equipped in certain areas with a recess area designed by way of an example as a rectangle but not described in any more detail, lies flat on a surface 116 of the embossed area 112, drawn hatched in FIG. 6 and, purely by way of an example, designed as a rectangle, and can be connected in an adhesively bonded manner, preferably through gluing or welding, to the embossed area 112.

The sixth embodiment of a profiled blade 121 according to the described system shown in FIG. 7 is a version of the profiled blade 101 in which, additionally, embossed areas 113 are introduced into the second end zone 131 along the end zone edge 126, preferably at an equal distance from each other. These embossed areas 113 are, relative to the first end zone 110, introduced recessed into the second end zone 111 and extend, originating from the end zone edge 106, in the direction of the leading edge 118.

The seventh embodiment of a profiled blade 141 according to the described system shown in FIG. 8 is a version of the profiled blade 121 according to FIG. 7, in which only the curvatures of the profiled parts 157, 158 are changed. Here the upper profiled part 157 has a concave outer surface, whilst the lower profiled part 158 has a convex outer surface. By way of an example it can be provided that the profiled blades 21, 41, 61, 101, 121, 141 previously described are used to produce a fan wheel 90, as is shown in FIG. 5 purely by way of an example with profiled blades 21 mounted on it. Such a fan wheel 90 is used to transport a gaseous fluid and comprises, purely by way of an example, several blades 21 which are arranged at a pre-settable angular division in a ring-shaped spatial volume around an axis of rotation 92. The blades 21 are each fixed with their axial, opposing end zones, to supports 93, 94. Here a first support is designed as a disc-shaped round plate 93 coaxial to the axis of rotation 92 and comprises a hub arrangement 95. A support, by contrast, is designed as ring 94 coaxial to the axis of rotation 92. It is provided that the profile blades 21 are each arranged with the leading edge 38 radially inward, while the end zones 30, 31, connected to each other in an adhesively bonded manner, are arranged radially outward. Thanks to the curvatures of the two profiled parts 37, 39, when the fan wheel 90 rotates around the axis of rotation 92 in a direction of rotation which as per the view from FIG. 5 is clockwise, a reverse rotation of the profiled blades 21 is generated by which an axial flow of fluid takes place along the axis of rotation 92 through the ring 94 into the ring-shaped spatial volume and from there in a radial direction to the outside. Here the fluid first flows towards the leading edge 38 of the profiled blades 21, and subsequently flows away along the profiled parts 37, 39 in a radial direction towards the outside. Purely by way of an example it is provided that the profiled blades 21 are welded at least almost fully along the front-end profile edges 40 to the disc-shaped round plate 93 and the ring 94. Through the design of the profiled blades 21 as profile bodies 27, a high-strength and cost-effective fan wheel 90 is achieved in an interaction with the disc-shaped round plate 93 and the ring 94. 

What is claimed is:
 1. A profiled blade for a fan wheel, comprising: a profile body made from at least one curved metal strip, wherein adjacent first and second end zones of the least one metal strip are connected in an adhesively bonded and/or form-fit manner to each other, and wherein the second end zone is equipped with at least one embossed area at a distance from a second end zone edge for the formation of a contact surface to enable an at least partial contact with the first end zone.
 2. The profiled blade according to claim 1, wherein a first end zone edge of the first end zone is arranged at a distance from a second end zone edge of the second end zone and that the first end zone edge is fixed on an upper side of the second end zone facing towards the first end zone.
 3. The profiled blade according to claim 2, wherein the profile body includes a first profiled part, a second profiled part, and a sleeve-shaped, highly curved leading edge, the first profiled part enclosing the first end zone and being connected to the sleeve-shaped, highly curved leading edge, the sleeve-shaped, highly curved leading edge being connected to the second profiled part, which ends at the second end zone.
 4. The profiled blade according to claim 3, wherein the leading edge has a convexly curved outer surface and/or the first profiled part has a convexly curved outer surface and/or the second profiled part has a concavely curved outer surface.
 5. The profiled blade according to claim 3, wherein the first profiled part and/or the second profiled part are plate-shaped.
 6. The profiled blade according to claim 1, wherein the embossed area is shaped as corrugation and is located at a distance from the second end zone edge.
 7. The profiled blade according to claim 1, wherein the embossed area protrudes from the upper side of the second end zone.
 8. The profiled blade according to claim 7, wherein the embossed area has an L-shaped profile.
 9. The profiled blade according to claim 1, wherein the embossed area is recessed in the upper side of the second end zone.
 10. The profiled blade according to claim 9, wherein the embossed area has an L-shaped profile.
 11. The profiled blade according to claim 1, wherein the profile body is designed open on the front side and/or is formed from precisely one one-piece, bent metal strip.
 12. The profiled blade according to claim 1, wherein the first end zone edge is welded and/or glued to the upper side of the second end zone facing towards the first end zone.
 13. A fan wheel for transporting a gaseous fluid, comprising: a disc-shaped round plate arranged coaxially with an axis of rotation and comprising a hub arrangement; a ring arranged coaxially with the axis of rotation and at a distance from the round plate; and a plurality of profiled blades according to claim 1 arranged in a pre-settable angular division in a ring-shaped spatial volume around the axis of rotation, fixed with axial, opposing faces on the round plate and on the ring.
 14. The fan wheel according to claim 13, wherein the profiled blades each have a leading edge arranged radially inward in the ring-shaped spatial volume and first end zones and second end zones arranged radially outward in the ring-shaped spatial volume.
 15. A method for producing a profiled blade, the method comprising: supplying a metal strip to an embossing device; carrying out an embossing process to emboss an embossed area into a second end zone of the metal strip; supplying the embossed metal strip to a metal forming device and deforming the metal strip to form a leading edge, a first profiled part and a second profiled part; bringing into contact a first end zone edge of a first end zone with an upper side of the second end zone facing towards the first end zone; and connecting the first end zone edge to the upper side of the second end zone by adhesive bonding.
 16. The method according to claim 15, wherein the embossing process comprises performing deformation of the metal strip and/or a separation process for separating the metal strip from a metal sheet.
 17. The method according to claim 15, wherein the first end zone edge is welded to the upper side of the second end zone and profiled blades formed thereby are each welded on the front side to a disc-shaped round plate and to a ring arranged coaxially to and at a distance from the round plate, in each case along a profile outer edge going all the way around. 